The location, conformation and dynamics of gramicidin A and valinomycin are studied in bilayer lipid vesicles. The principal experimental method is 1HNMR spectroscopy of the molecule of interest. Using a newly developed organic synthesis procedure, perdeuterated phospholipids are synthesized and used as the membrane matrix, in order to attenuate background 1HNMR signals. Nitroxide spin-labeled lipids are used as relaxation enhancement probes to locate amino acid residues of the gramicidin or valinomycin within the membrane.